Geographically, climatically and environmentally deterministic forms of knowledge have ancient roots, often being traced back to Herodotus. As the likes of Mike Hulme have recently argued, such epistemic tendencies are evident in forms of climate science that project narrowly defined human futures on the basis of abstract and reductionist calculative practices. To so much as have a conversation about ‘the Anthropocene’ requires some degree of discursive absorption of the progressive produce of calculative rationality. However, there is equally an imperative not to turn the looming spectre of vast, inhuman forces into deterministic narratives that paralyse political possibility. This paper will build on a discussion session that I arranged at the RGS-IBG conference in September 2015. It will, first, set out a brief history of determinism and its critics and, second, engage with contemporary speculative philosophical debates around geophilosophy and geopolitics in order to begin to creatively re-articulate how determinism can be intellectually and politically overcome without lapsing into voluntaristic denial of the crushingly urgent facts of the Anthropocene. In short, it attempts to articulate an updated form of possibilism that might help to facilitate the production of future geopolitical analyses—and future geopolitics.